Ok, so I' ve downloaded only part 1 but same as in part 1 you will have to do witho other parts.
So after downloading you get .rar file you don't have to extract it just place it in deskop for easier work. First install yhe vehicles meta. To do that you will need OPEN IV (if you don't have it just download it from this site https://openiv.com/ . Firstly when you open this programme you have to click tools, than asi manager and install all components. Then you have to go to mods folder (if you don't have this just create folder named "mods" in GTA V main folder and copy to it 2 files: 'update" and "x64", it can take some time but it will create something like special zone for mods, so if something goes wrong just delete mods folder and the game will work.)
If you are done with you need to go to folder using OPEN IV just go this path: mods > update > update.rpf > common > data > levels > gta5 and search for "vehicles.meta". Click "edit mode" in the upper part and simply drage the vehicles.meta from your pack to OPEN IV. (only file not folder). After that you have just installe meta. Next step is create two folders on deskop. Name first "Models" and second "VCF". Than go into folder with car that you want to have (I can see that some are using same slots so you can't have for example all CVPI). Then you are putting all .yft and .ytd files into "Models" folder (2 .yft files and 1 or 2 .ytd [some cars have two ytd some have only one]). Than you put .xml file into "VCF" folder. Do it in every car you want. In parts 2 and 3 you' ve got vehicles meta too, but it's same file for all cars, so you don't have to install it second time. After you copy all car file to suitable folders open OPEN IV again, click "Edit Mode" and go: mod > update > x64 > dlcpacks > patchday22ng > dlc,rpf > x64 > levels > gta5 > vehicles.rpf .
And drag all files from "Models" folder on your deskop into OPEN IV (remember not folder only files). Than copy all from "VCF" to pack deflaut into ELS folder (just like you have it now). If everything goes correct run GTA V with Rage Plugin Hook, type Spawn POLICE into console (F4) and enjoy your new car.
Hope this will help you
ps. Read the ELS manual about keys, because the are really lots of them.